<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<div id="app">

  <!--写法一-->
  <h2 v-if="score > 90">优秀</h2>
  <h2 v-else-if="score > 80">良好</h2>
  <h2 v-else-if="score > 60">及格</h2>
  <h2 v-else>不及格</h2>
  <!--写法二-->
  <h2>{{result}}</h2>
</div>

<script src="../js/vue.js"></script>
<script>
  const app = new Vue({
    el: '#app',
    data: {
      score: 55
    },
    computed: {
      result() {
        let message = "";
        if (this.score > 90) {
          message = '优秀';
        } else if (this.score > 80) {
          message = '良好';
        } else if (this.score > 60) {
          message = '及格'
        } else {
          message = '不及格'
        }
        return message
      }
    }
  })
</script>

</body>
</html>
